In recent years, several methods have been developed for directly introducing foreign genes into animal or human bodies in the hope of applying them to gene therapy for treating diseases caused by genomic abnormalities.
Diseases caused by congenital gene abnormalities such as congenital gene deficiency are preferably treated in the prenatal stage. As regards introduction of genes into prenatal subjects, microinjection into fertilized egg in animal experiments is the sole method that is currently available [Palmitter, R. D. & Brinster, R. L.: Annu. Rev. Genet., 20, 465-499 (1986)].
Although the microinjection method applied to fertilized egg opened the way for introduction of genes into early embryogenic stage, means for introducing foreign genes into fetuses has not yet been developed. Moreover, microinjection method cannot be applied to gene therapy of fetuses in the case of human pregnancy.
Accordingly, an object of the present invention is to develop a method for introducing foreign genes into fetuses in a developmental stage, and another object of the invention is to provide a gene-containing composition for use in such a method.